THE SPOOL TREE: FIRST APPLICATION OF A NEW SUBSEA WELLHEAD/TREE CONFIGURATION

The subsea Spool/Tree system (also known as "Horizontal" or "Valveless" tree) features a spool with a wellhead connector below and a wellhead connector profile on top; the tubing hanger is hung off inside the spool: the vales are situated on the side of the spool and there are no valves in the vertical bore of the wellhead/tree system. This configuration requires the well completion to be run after the tree has been installed, but it enables the completion to be pulled without the tree being removed. The running tools and accessories required for the Spool/Tree are simpler than for a conventional system. A description of the concept as applied for the first time in the Gryphon Field is provided. The novelty of the concept lies in the configuration of the equipment, not in the technology employed. The system offered cost and delivery time advantages, but of prime concern was the safety implication of using this novel equipment, and a comprehensive safety evaluation was carried out. The safety features of the Gryphon Spool/Tree system are described, and all 7 safety studies investigating the system from various angles are summarized. The final section addresses future potential applications of the concept.

• Supplemental Notes:
  • OTC 94, 26th Annual Offshore Technology Conf; 2-5 May 1994; Houston, Tx, USA. Procs. Vol 2, ppr 7427, p 65 [12 p, 2 ref, 5 fig]
• Authors:
  • Lopez, R H
  • Mansell, M
  • Stewart, A A
• Publication Date: 1994

Language

• English

Subject/Index Terms

• TRT Terms: Oil fields
• Old TRIS Terms: Wellheads
• Subject Areas: Marine Transportation;

Filing Info

• Accession Number: 00708602
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM